code: def test_update_with_different_dtype(self, using_copy_on_write):
      # GH#3217
      df = DataFrame({"a": [1, 3], "b": [np.nan, 2]})
      df["c"] = np.nan
      with tm.assert_produces_warning(
          FutureWarning, match="incompatible dtype"
      ):
          df.update({"c": Series(["foo"], index=[0])})
  
      expected = DataFrame(
          {
              "a": [1, 3],
              "b": [np.nan, 2],
              "c": Series(["foo", np.nan], dtype="object"),
          }
      )
      tm.assert_frame_equal(df, expected)
  
file_path: pandas/pandas/tests/frame/methods/test_update.py
imports: import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Series, date_range
  import pandas._testing
label_desc: Use image node_id 11 for calling the TestDataFrameUpdate obj's underlying member method code with example usage: obj.test_update_with_different_dtype(using_copy_on_write) without return types